Bug#752587: libtcl-perl: FTBFS: croak -Werror=format-security violations

[Aaron M. Ucko]

Source: libtcl-perl
Version: 1.02+ds-1
Severity: serious
Justification: fails to build from source

Builds of libtcl-perl have been failing with errors of the form

  Tcl.xs: In function 'XS_Tcl_Eval':
  Tcl.xs:1032:6: error: format not a string literal and no format arguments [-Werror=format-security]
        croak(Tcl_GetStringResult(interp));
        ^

though for some reason only on 32-bit systems; see, for instance,

https://buildd.debian.org/status/fetch.php?pkg=libtcl-perl&arch=i386&ver=1.02%2Bds-1&stamp=1403615476

Could you please take a look?

Thanks!